The present Invention relates to a cloth adhesive tape for binding a wire harness used for binding the insulated conductors of a wire harness, and in particular, a cloth adhesive tape for binding a wire harness, which does not contain any halogen element and has good characteristics of a sound-damping property, a hand-tearing property, a fire resistance and the like and does not cause a delamination in a substrate and is manufactured at low cost. Here, the sound-damping property means a property of damping sounds produced when substances are put into contact with each other, and the hand-tearing property means a property of being torn or broken in a vertical direction or in a slanting direction with respect to the direction of the length of the adhesive tape by the tensile stress caused by hands. Also, the delamination means a phenomenon that a substrate of the adhesive tape is separated into two layers of an adhesive layer side and a resin layer side when the adhesive tape reel in multiple turns is unwound. The adhesive tape causing the delamination in a wide range can not be used for a true purpose.
An adhesive tape having a substrate made of polyvinyl chloride has mainly been used as an adhesive tape for binding a wire harness. Also, an adhesive tape having a substrate made of a cotton cloth or an acetate cloth has been used to reduce tapping noises or friction noises produced by the wire harness from the viewpoint of improving the cabin comfort of a car.
The adhesive tape having a substrate made of polyvinyl chloride is inexpensive, but when it is burned, it is apt to generate dioxin and hence sometimes presents an environmental problem. Also, when the adhesive tape having a substrate made of polyvinyl chloride is used for binding the wire harness, it can produce good workability but it can not satisfactorily prevent noises such as tapping noises, friction noises or the like.
Also, an adhesive tape having a substrate made of a cotton cloth or an acetate cloth, which is disclosed in Japanese Utility Model Laid-Open No. 4-643, can prevent noises such as tapping noises, friction noises or the like, but it is expensive.
Also, an adhesive tape having a substrate made of a non-woven fabric, which is disclosed in Japanese Utility Model Laid-Open No. 2-53950, is not expensive and has an effect of preventing noises such as tapping noises, friction noises or the like, but it is apt to cause a delamination when the adhesive tape reel in multiple turns is unwound.
As described above, the conventional technologies have not been capable of producing an adhesive tape for binding a wire harness, which does not contain any halogen element and is excellent in a sound-damping property, a hand-tearing property and a fire resistance and does not cause a delamination in the substrate and is manufactured at low cost.
The present invention has been made to solve the above problems. It is an object of the present invention to provide an adhesive tape for binding a wire harness, which does not contain any halogen element and is excellent in sound-damping property, hand-tearing property and fire resistance and does not cause a delamination in the substrate and is manufactured at low cost.
In order to accomplish the object described above, a cloth adhesive tape for binding a wire harness in accordance with the present invention includes an adhesive layer put on the one surface of the substrate made of a non-woven fabric having small through holes throughout the area thereof, a resin layer put on the surface of the substrate opposite to the surface provided with the adhesive layer, and a release agent layer put on the resin layer.
In this case, for example, a cotton non-woven fabric having a thickness of 0.2 mm to 0.6 mm and containing no binder is used as the non-woven fabric. The non-woven fabric like this has impact relaxing property because its thickness is not less than 0.2 mm, and is easy to use because its thickness is not more than 0.6 mm and hence is easily torn by hands. The use of this non-woven fabric as a substrate makes it possible to manufacture an adhesive tape for binding a wire harness having a good sound-damping property and a good hand-tearing property and can reduce the total cost of the adhesive tape because the substrate is not expensive.
Also, in this case, the delamination of the substrate (that is, non-woven fabric) can be prevented by making small through holes in the whole area of the non-woven fabric. The reason why the through holes prevent the delamination of the non-woven fabric is that when resin such as polyethylene is laminated on the non-woven fabric to reinforce the non-woven fabric, the resin such as polyethylene gets into the through holes to reinforce the portions near the through holes of the non-woven fabric. That is, even if the non-woven fabric causes the delamination, the delamination is caused only near the peripheral portions of the through holes reinforced particularly in this manner and is not caused in the wide range of the non-woven fabric.
Also, it is preferable that the diameter of the aperture of the through holes on the surface of the non-woven fabric described above is 0.5 mm to 2 mm. If the diameter of the aperture is not more than 0.5 mm, the resin slightly gets into the through holes and does not reinforce the non-woven fabric. Also, if the diameter of the aperture is not less than 2 mm, there is a portion where a distance between the apertures is not less than 2 mm and the non-woven fabric is not sufficiently reinforced at the portion. Therefore, there is a danger in both the cases that the delamination is caused. Further, it is preferable that the total area of the apertures of the through holes described above is 10% to 35% of the surface area of the non-woven fabric described above. If the total area of the apertures of the through holes described above is less than 10% of the surface area of the non-woven fabric, the non-woven fabric is not sufficiently reinforced, and if the total area of the apertures of the through holes described above is more than 35% of the surface area of the non-woven fabric, the ratio of the non-woven fabric to the whole area of the tape is made small, which reduces a sound-damping effect. Since the area of the aperture of one through holes is not more than 3.2 mm2 under this condition, there is on the average one or more through holes per 32 mm2 of the surface area of the non-woven fabric described above. Further, the shape of the aperture of the through hole is not particularly limited to a circle.
Furthermore, in this case, since the release agent layer described above is between the adhesive layer and the resin layer when the adhesive tape is wound many turns, when the adhesive tape is unwound, the release agent layer is easily peeled off from the adhesive layer with the resin layer to prevent the delamination.
Also, in this case, the adhesive layer is made by applying an adhesive composition containing, for example, cis-1, 4-polyisoprene as a base material and a flame retardant or a fire resistant agent containing no halogen element on the substrate. Natural rubber (cis-1, 4-polyisoprene derived from plants) or synthetic cis-1, 4-polyisoprene or a mixture of both of them is used as the cis-1, 4-polyisoprene. The adhesive layer like this does not contain halogen element and hence does not generate dioxin when it is burned.
Also, in this case, for example, a polyethylene layer having a thickness of 10 xcexcm to 45 xcexcm is used as the resin layer. Such a polyethylene layer has a thickness of 10 xcexcm or more and hence can reinforce the non-woven fabric sufficiently. Also, the polyethylene layer has a thickness of 45 xcexcm or less and hence does not impair the hand-tearing property of the tape.
Also, in this case, the resin layer may be made of a polyethylene layer colored black by carbon black and embossed and having a thickness of 10 xcexcm to 45 xcexcm. If an adhesive tape provided with such a polyethylene layer in accordance with the present invention is used for binding a wire harness, it can make the wire harness inconspicuous.